src/bin/lttng/commands/view.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26
  27 #include "../command.h"
  28 #include <config.h>
  29
  30 static char *opt_session_name;
  31 static char *opt_viewer;
  32 static char *opt_trace_path;
  33 static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
  34 //static const char *lttv_gui_bin = CONFIG_LTTV_GUI_BIN;
  35
  36 enum {
  37         OPT_HELP = 1,
  38         OPT_LIST_OPTIONS,
  39 };
  40
  41 static struct poptOption long_options[] = {
  42         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  43         {"help",        'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  44         {"list-options", 0,  POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  45         {"viewer",      'e', POPT_ARG_STRING, &opt_viewer, 0, 0, 0},
  46         {"trace-path",  't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
  47         {0, 0, 0, 0, 0, 0, 0}
  48 };
  49
  50 /*
  51  * This is needed for each viewer since we are using execvp().
  52  */
  53 static const char *babeltrace_opts[] = { "babeltrace" };
  54 //static const char *lttv_gui_opts[] = { "lttv-gui", "-t", };
  55
  56 /*
  57  * Type is also use as the index in the viewers array. So please, make sure
  58  * your enum value is in the right order in the array below.
  59  */
  60 enum viewer_type {
  61         VIEWER_BABELTRACE    = 0,
  62         VIEWER_LTTV_GUI      = 1,
  63         VIEWER_USER_DEFINED  = 2,
  64 };
  65
  66 /*
  67  * NOTE: "lttv" is a shell command and it's not working for exec() family
  68  * functions so we might think of removing this wrapper or using bash.
  69  */
  70 static struct viewers {
  71         const char *exec_name;
  72         enum viewer_type type;
  73 } viewers[] = {
  74         { "babeltrace", VIEWER_BABELTRACE },
  75         { "lttv-gui", VIEWER_LTTV_GUI },
  76         { NULL, VIEWER_USER_DEFINED },
  77 };
  78
  79 /*
  80  * usage
  81  */
  82 static void usage(FILE *ofp)
  83 {
  84         fprintf(ofp, "usage: lttng view [SESSION_NAME] [OPTIONS]\n");
  85         fprintf(ofp, "\n");
  86         fprintf(ofp, "By default, the babeltrace viewer will be used for text viewing\n");
  87         fprintf(ofp, "\n");
  88         fprintf(ofp, "Where SESSION_NAME is an optional session name. If not specified, lttng will\n");
  89         fprintf(ofp, "get it from the configuration file (.lttngrc).\n");
  90         fprintf(ofp, "\n");
  91         fprintf(ofp, "Options:\n");
  92         fprintf(ofp, "  -h, --help               Show this help\n");
  93         fprintf(ofp, "      --list-options       Simple listing of options\n");
  94         fprintf(ofp, "  -t, --trace-path PATH    Trace directory path for the viewer\n");
  95         fprintf(ofp, "  -e, --viewer CMD         Specify viewer and/or options to use\n");
  96         fprintf(ofp, "                           This will completely override the default viewers so\n");
  97         fprintf(ofp, "                           please make sure to specify the full command. The trace\n");
  98         fprintf(ofp, "                           directory path of the session will be appended at the end\n");
  99         fprintf(ofp, "                           to the arguments\n");
 100         fprintf(ofp, "\n");
 101 }
 102
 103 static struct viewers *parse_options(void)
 104 {
 105         if (opt_viewer == NULL) {
 106                 /* Default is babeltrace */
 107                 return &(viewers[VIEWER_BABELTRACE]);
 108         }
 109
 110 #if 0
 111         if (strstr(opt_viewer, viewers[VIEWER_LTTV_GUI].exec_name) == 0) {
 112                 return &(viewers[VIEWER_LTTV_GUI]);
 113         }
 114 #endif
 115
 116         /*
 117          * This means that if -e, --viewers is used, we just override everything
 118          * with it. For supported viewers like lttv, we could simply detect if "-t"
 119          * is passed and if not, add the trace directory to it.
 120          */
 121         return &(viewers[VIEWER_USER_DEFINED]);
 122 }
 123
 124 /*
 125  * Alloc an array of string pointer from a simple string having all options
 126  * seperated by spaces. Also adds the trace path to the arguments.
 127  *
 128  * The returning pointer is ready to be passed to execvp().
 129  */
 130 static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
 131 {
 132         int i = 0, ignore_space = 0;
 133         unsigned int num_opts = 1;
 134         char **argv, *token = opts;
 135
 136         /* Count number of arguments. */
 137         do {
 138                 if (*token == ' ') {
 139                         /* Use to ignore consecutive spaces */
 140                         if (!ignore_space) {
 141                                 num_opts++;
 142                         }
 143                         ignore_space = 1;
 144                 } else {
 145                         ignore_space = 0;
 146                 }
 147                 token++;
 148         } while (*token != '\0');
 149
 150         /* Add two here for the NULL terminating element and trace path */
 151         argv = malloc(sizeof(char *) * (num_opts + 2));
 152         if (argv == NULL) {
 153                 goto error;
 154         }
 155
 156         token = strtok(opts, " ");
 157         while (token != NULL) {
 158                 argv[i] = strdup(token);
 159                 token = strtok(NULL, " ");
 160                 i++;
 161         }
 162
 163         argv[num_opts] = (char *) trace_path;
 164         argv[num_opts + 1] = NULL;
 165
 166         return argv;
 167
 168 error:
 169         return NULL;
 170 }
 171
 172 /*
 173  * Alloc an array of string pointer from an array of strings. It also adds
 174  * the trace path to the argv.
 175  *
 176  * The returning pointer is ready to be passed to execvp().
 177  */
 178 static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
 179                 const char *trace_path)
 180 {
 181         char **argv;
 182         size_t size;
 183
 184         size = sizeof(char *) * opts_len;
 185
 186         /* Add two here for the trace_path and the NULL terminating element. */
 187         argv = malloc(size + 2);
 188         if (argv == NULL) {
 189                 goto error;
 190         }
 191
 192         memcpy(argv, opts, size);
 193
 194         argv[opts_len] = (char *)trace_path;
 195         argv[opts_len + 1] = NULL;
 196
 197 error:
 198         return argv;
 199 }
 200
 201 /*
 202  * Spawn viewer with the trace directory path.
 203  */
 204 static int spawn_viewer(const char *trace_path)
 205 {
 206         int ret = 0;
 207         struct stat status;
 208         const char *viewer_bin = NULL;
 209         struct viewers *viewer;
 210         char **argv = NULL;
 211
 212         /* Check for --viewer options */
 213         viewer = parse_options();
 214         if (viewer == NULL) {
 215                 ret = CMD_ERROR;
 216                 goto error;
 217         }
 218
 219         switch (viewer->type) {
 220         case VIEWER_BABELTRACE:
 221                 if (stat(babeltrace_bin, &status) == 0) {
 222                         viewer_bin = babeltrace_bin;
 223                 } else {
 224                         viewer_bin = viewer->exec_name;
 225                 }
 226                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 227                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 228                 break;
 229 #if 0
 230         case VIEWER_LTTV_GUI:
 231                 if (stat(lttv_gui_bin, &status) == 0) {
 232                         viewer_bin = lttv_gui_bin;
 233                 } else {
 234                         viewer_bin = viewer->exec_name;
 235                 }
 236                 argv = alloc_argv_from_local_opts(lttv_gui_opts,
 237                                 ARRAY_SIZE(lttv_gui_opts), trace_path);
 238                 break;
 239 #endif
 240         case VIEWER_USER_DEFINED:
 241                 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
 242                 if (argv) {
 243                         viewer_bin = argv[0];
 244                 }
 245                 break;
 246         default:
 247                 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
 248                 argv = alloc_argv_from_local_opts(babeltrace_opts,
 249                                 ARRAY_SIZE(babeltrace_opts), trace_path);
 250                 break;
 251         }
 252
 253         if (argv == NULL) {
 254                 ret = CMD_FATAL;
 255                 goto error;
 256         }
 257
 258         DBG("Using %s viewer", viewer_bin);
 259
 260         ret = execvp(viewer_bin, argv);
 261         if (ret) {
 262                 if (errno == ENOENT) {
 263                         ERR("%s not found on the system", viewer_bin);
 264                 } else {
 265                         PERROR("exec: %s", viewer_bin);
 266                 }
 267                 free(argv);
 268                 ret = CMD_FATAL;
 269                 goto error;
 270         }
 271
 272 error:
 273         return ret;
 274 }
 275
 276 /*
 277  * Exec viewer if found and use session name path.
 278  */
 279 static int view_trace(void)
 280 {
 281         int ret;
 282         char *session_name, *trace_path;
 283         struct lttng_session *sessions = NULL;
 284
 285         /*
 286          * Safety net. If lttng is suid at some point for *any* useless reasons,
 287          * this prevent any bad execution of binaries.
 288          */
 289         if (getuid() != 0) {
 290                 if (getuid() != geteuid()) {
 291                         ERR("UID does not match effective UID.");
 292                         ret = CMD_ERROR;
 293                         goto error;
 294                 } else if (getgid() != getegid()) {
 295                         ERR("GID does not match effective GID.");
 296                         ret = CMD_ERROR;
 297                         goto error;
 298                 }
 299         }
 300
 301         /* User define trace path override the session name */
 302         if (opt_trace_path) {
 303                 session_name = NULL;
 304         } else if(opt_session_name == NULL) {
 305                 session_name = get_session_name();
 306                 if (session_name == NULL) {
 307                         ret = CMD_ERROR;
 308                         goto error;
 309                 }
 310         } else {
 311                 session_name = opt_session_name;
 312         }
 313
 314         DBG("Viewing trace for session %s", session_name);
 315
 316         if (session_name) {
 317                 int i, count, found = 0;
 318
 319                 /* Getting all sessions */
 320                 count = lttng_list_sessions(&sessions);
 321                 if (count < 0) {
 322                         ERR("Unable to list sessions. Session name %s not found.",
 323                                         session_name);
 324                         MSG("Is there a session daemon running?");
 325                         ret = CMD_ERROR;
 326                         goto free_error;
 327                 }
 328
 329                 /* Find our session listed by the session daemon */
 330                 for (i = 0; i < count; i++) {
 331                         if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
 332                                 found = 1;
 333                                 break;
 334                         }
 335                 }
 336
 337                 if (!found) {
 338                         MSG("Session name %s not found", session_name);
 339                         ret = CMD_ERROR;
 340                         goto free_sessions;
 341                 }
 342
 343                 trace_path = sessions[i].path;
 344
 345                 if (sessions[i].enabled) {
 346                         WARN("Session %s is running. Please stop it before reading it.",
 347                                         session_name);
 348                         ret = CMD_ERROR;
 349                         goto free_sessions;
 350                 }
 351         } else {
 352                 trace_path = opt_trace_path;
 353         }
 354
 355         MSG("Trace directory: %s\n", trace_path);
 356
 357         ret = spawn_viewer(trace_path);
 358         if (ret < 0) {
 359                 /* Don't set ret so lttng can interpret the sessiond error. */
 360                 goto free_sessions;
 361         }
 362
 363 free_sessions:
 364         free(sessions);
 365 free_error:
 366         if (opt_session_name == NULL) {
 367                 free(session_name);
 368         }
 369 error:
 370         return ret;
 371 }
 372
 373 /*
 374  * The 'view <options>' first level command
 375  */
 376 int cmd_view(int argc, const char **argv)
 377 {
 378         int opt, ret = CMD_SUCCESS;
 379         static poptContext pc;
 380
 381         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 382         poptReadDefaultConfig(pc, 0);
 383
 384         while ((opt = poptGetNextOpt(pc)) != -1) {
 385                 switch (opt) {
 386                 case OPT_HELP:
 387                         usage(stdout);
 388                         goto end;
 389                 case OPT_LIST_OPTIONS:
 390                         list_cmd_options(stdout, long_options);
 391                         goto end;
 392                 default:
 393                         usage(stderr);
 394                         ret = CMD_UNDEFINED;
 395                         goto end;
 396                 }
 397         }
 398
 399         opt_session_name = (char*) poptGetArg(pc);
 400
 401         ret = view_trace();
 402
 403 end:
 404         poptFreeContext(pc);
 405         return ret;
 406 }